1. Field of the Invention
Embodiments relate to the field of non-volatile storage and more particularly to a method, system and structure for treating patterned device structures with ions.
2. Discussion of Related Art
In present day technology many advanced devices such as sensors, processors, and memory devices include three dimensional structures that are fabricated from multilayer structures formed on a substrate. The fabrication of final structures having the desired shape and size presents many challenges in part due to the often complex system of different materials used to form the multilayer structures as well, as the extremely small size of many device structures. To cite one example, in the area of magnetic memory, much recent effort has focused on developing magnetic random access memory (MRAM) by patterning an array of isolated magnetic memory cells. This patterning may be performed by lithographically defining mask features on a substrate and etching the substrate with the mask in place to define a two dimensional array of memory cells having a generally planar geometry similar to conventional semiconductor RAM memory devices. However, each magnetic memory cell is composed of multiple different layers, including magnetic layers, insulator layers, conducting non-magnetic layers, and so forth. To define each isolated three dimensional MRAM cell an entire stack of such layers must be etched in regions between the memory cells to be formed. Leaving aside the etching challenges inherent in simply etching through such a stack of heterogeneous materials, the final three dimensional etched cells may present a less than ideal structure. In particular, the three dimensional structures may have sidewall layers that form during the etching process and require subsequent removal. Such redeposition alters the critical dimension of memory structures being patterned. In addition, such layers may have unknown or variable composition that typically include metallic material that may not be easily etched using conventional approaches such as wet etching or reactive ion etching without compromising the final device structures. It is with respect to these and other considerations that the present improvements have been needed.